1. Field of the Invention
The present invention relates to lead silicate glasses.
2. Description of the Prior Art
Photosensitivity, the long-term change of glass refractive index following optical irradiation, has found application in telecommunications see A. Othonos, Rev. Sci. Instrum. 68, 4309 (1997), and data storage, see A. Partovi, T. Erdogan, V. Mizrahi, P. J. Lemaire, A. M. Glass and J. W. Fleming, Appl Phys. Lett. 64, 821 (1994). The preponderance of the investigations in optical fiber have been devoted to germanosilicate glasses with An, the index difference between irradiated and non-irradiated material, saturating at about 0.01 for hydrogen loaded fibers with limited stability at elevated temperatures, see A. Othonos, Rev. Sci. Instrum. 68, 4309 (1997). For data storage, crystalline phase change materials have been explored because of the large index changes available. However, these materials are not useful for fiber applications. Therefore, there exists a need for glasses with higher photosensitivity for improved performance in both fiber and volume storage applications.
It is therefore an object of the present invention to provide a method for forming lead silicate glass materials having large, thermally stable photosensitivities.
It is another object of the present invention to provide a method for forming lead silicate glass materials that may be for used in telecommunications, integrated optics and data storage technologies.
It is yet another object of the present invention to provide a method for forming glasses with higher photosensitivity for improved performance in both fiber and volume storage applications.
According to a first broad aspect of the present invention, there is provided a method for inducing a refractive index change in a lead silicate glass material comprising: providing a lead silicate glass material; and irradiating the lead silicate glass material to increase the index of refraction of said lead silicate glass material.
According to a second broad aspect of the present invention, there is provided a photo-induced lead silicate glass grating.
Other objects and features of the present invention will be apparent from the following detailed description of the preferred embodiment.